Tunnels for Sale

I found this is the New York Times:

For sale: a vast tunnel complex in central London. Former tenants include Britain’s secret service, the famous hot line between America and the Soviet Union during the cold war and 400 tons of government documents. The asking price is $7.4 million.

I remember fantasizing about living underground as a young and very peculiar teenager. I think I got the idea from a film—I can’t remember which one.